A borer-infested Victorian cabinet filled with seventy two birds that were in dire need of attention, presented quite a challenge for Conservator, Felicity Bolton.

In the eyes of an insect, the case presents quite the feast with its various sources of protein such as feathers, skin and other organic matter, so our conservator, Felicity, first looked for signs of insect activity.

The immediate problem was evidence of an active borer infestation in the frame of the case , and further inspection inside the case revealed cast larvae skins of the Dermestid beetle and insect faeces, similar to fine sand, known as frass. On seeing evidence of frass, our conservators initial thoughts were, ‘is this fresh?’.

Evidence of fresh frass is a cause of great concern as it shows that an active pest infestation has taken place, so great measures are taken to arrest any more feasting. Sadly for one of the birds, insects had already taken its toll by nibbling off its tail (pictured below), so although the case had been treated with a fumigant in April 2006, the team weren’t taking any chances.

Blast-freeze treatment

The team removed the back of the case wearing full protective clothing as there was no documentation on what potentially hazardous pesticides were used in the case. To further prevent the inhalation of toxic fumes during the removal of the birds, a fume extractor was placed overhead to remove any chemical odours that could be harmful to staff. The tree-like structure and birds were then removed from its case, bolstered with an aluminium mount, and placed in the Museum’s large freezer to kill off living pests. The original glass frontage of the case could not be frozen as there was a risk that it could crack in the freezer, so the cabinet was placed in a chamber where all the oxygen was removed and the air was replaced with nitrogen to blitz any insects.

Once the pest treatment was completed, some detailed conservation work was performed on each of the birds. Each bird received a low-suction vacuum to remove dirt, dust and frass. Following this, the cast skins were removed using tweezers and finally given a wet-clean, using a cotton swab dampened with distilled water and a few drops of industrial alcohol. To repair the broken branches, splints were made and tied onto the stubs. The loose leaves also received a light mist of steam with a soft brush to relax them into a natural shape.

Bird surgery

For birds with missing limbs it was a much more involved job that required ingenuity, a steady hand and experimentation. For the tail-less bird, conservation putty was added to the nibbled tissue of the bird’s tail-end to strengthen it, then a piece of stainless steel was added to the end of the tail. This bolstered tail was then inserted into the bird’s rear.

Another bird had completely lost its head, so returning it to its original state required significant conservation work. Firstly a piece of fabric lining was adhered to the inner part of the head and neck and later, the lined head was sewn onto the bird’s neck using thread and a small curved needle. It was then given a light mist of steam to help smooth out some of the untidy, ruffled feathers and provide definition and shape.

The Greater Yellowlegs specimen before and after surgery.

Having finished this mammoth task, the birds were returned to the case in their newly spruced-up form. We’ll be keeping an eye on them to ensure insects stay at bay, so this magnificent cabinet of curiosity survives into the future.

This Victorian cabinet piqued the interest of applied arts curator, Grace Lai, so she conducted some detective work on this piece. Find out more by reading her blog, Cabinet of avian curiosities.

Post by: Felicity Bolton

Felicity has a background in natural science/object conservation. She is currently works as a project conservator at the Museum.